Sulfur mustard and biological ageing: A multisystem biological health score approach as an extension of the allostatic load in Sardasht chemical veterans

Health assessment of sulfur mustard-chemical veterans with various respiratory diseases: The result of a comparative analysis of biological health scores (BHS) through 50 biomarkers

BACKGROUND

Mustard gas as a chemical weapon has been used in wars and its long-term side effects are substantial in the human body. This study aimed to apply an extension of allostatic load, known as biological health score (BHS), including the wear-and-tear of four physiological systems (endocrine, inflammatory, cardiovascular, and metabolic systems) to estimate biological health caused by sulfur mustard (SM) toxicity.

METHODS

In this cross-sectional study, serum samples were collected from two distinct groups of male individuals including 1) 236 individuals who had been exposed to SM gas during the Iraq-Iran war in 1987. This group was divided into three subgroups based on their respiratory disorders (19 individuals with asthma, 92 individuals with bronchiolitis obliterans, and 125 individuals with chronic bronchitis); 2) 64 healthy members, at the same range of age and residence, as the non-exposed group. To estimate a modified BHS, 50 blood-derived biomarkers (or their ratios) of the mentioned systems were measured.

RESULTS

The SM-exposed group and respiratory disease subgroups exhibited higher BHS than controls (P < 0.05). The endocrine and metabolic systems exhibited higher BHS in the SM-exposed group and its subgroups compared to the control group (P < 0.05). In contrast, the cardiovascular and immune/inflammatory systems did not show significant differences between the groups. Principal component analysis (PCA) identified several key biomarkers, including lymphocyte count, the LDH/lymphocyte ratio, cholesterol levels, and neutrophil count, as major contributors to interpatient variation among individuals exposed to SM and those with related respiratory diseases.

CONCLUSION

The modified multisystem BHS could be useful in the more accurate evaluation of biological health in chronic SM toxicity. The dysregulation observed in the endocrine and metabolic systems underscores the complication of SM toxicity and its extensive consequences on physiological homeostasis.

Evaluation of serum BDNF, IL-1β, and IL-6 levels alongside assessing mental health and life satisfaction in sulfur mustard-chemical veterans

Sulfur mustard (SM), a chemical warfare weapon has been used in conflicts. The delayed impact of sulfur mustard on mental and physical health of veterans remains a topic of significant concern. This cross-sectional study investigated the serum levels of brain-derived neurotrophic factor (BDNF), interleukin (IL)-1β, and IL-6 in 227 SM-chemical veterans receiving long-term financial support and 77 healthy individuals. Their mental health status and life satisfaction were assessed through three self-report questionnaires (General Health Questionnaire - 28, GHQ-28; Depression, Anxiety & Stress Scale, DASS-21; 36-Item Short Form Survey, SF-36). Our findings revealed higher levels of anxiety/insomnia, and psychiatric symptoms in the veterans compared to the control group (P < 0.05), accompanied by depression, stress, and anxiety as measured by the GHQ-28 and DASS-21 assessments. Severe depression and social dysfunction were not prevalent in the veterans compared to the control group (P > 0.05) according to the GHQ-28 findings. The SF-36 assessment indicated overall better health conditions for SM participants, with higher scores across various domains (general health, social function, and mental health) and two mental and physical dimensions in the veterans compared to the control group (P < 0.05). IL-1β and IL-6 levels were lower in the SM-exposed group than in the control group, while the BDNF level was higher in the SM-exposed group (P < 0.05). Alterations in BDNF, IL-1β, and IL-6 levels along with results of the mentioned questionnaires may be evidence of partial improvement in the mental and physical health of the SM-exposed individuals receiving the financial support.

Association of hormone profile with various respiratory disorders in sulfur mustard-chemical veterans

BACKGROUNDS

Chronic respiratory complications such as asthma, bronchiolitis obliterans, and chronic bronchitis are prevalent among individuals exposed to sulfur mustard (SM). This study investigates the hormonal changes associated with SM-induced respiratory disorders.

METHODS

A cross-sectional analysis was conducted involving 276 male participants exposed to SM during the Iraq-Iran war and 64 healthy controls. Serum levels of various hormones were measured.

RESULTS

Testosterone, dehydroepiandrosterone sulfate (DHEA-S), luteinizing hormone (LH), DHEA-S/cortisol ratio, and DHEA-S/prolactin ratio were decreased in the SM-exposed group compared to the control group while prolactin level and prolactin/cortisol ratio were increased (P < 0.05). The prolactin was increased in bronchiolitis obliterans, chronic bronchitis, and asthma compared to the control group while DHEA-S and DHEA-S/prolactin ratio were decreased in those disorders (P < 0.05). The testosterone was only decreased in asthma, and DHEA-S/cortisol ratio was only decreased in bronchiolitis obliterans and chronic bronchitis compared to control and other disorders (P < 0.05). The principle component analysis showed that the DHEA-S/cortisol and testosterone/cortisol ratios had the most contributing to interpatient variation in total SM-exposed patients in the principle component 1 (PC1). In patients with asthma and bronchiolitis obliterans, prolactin/cortisol and testosterone/cortisol ratios had the most contributing in PC1 while in patients with chronic bronchitis, the DHEA-S/cortisol and testosterone/cortisol ratios had the most contributing.

CONCLUSION

Hormones including testosterone, prolactin, and DHEA-S or their ratios (DHEA-S/cortisol and DHEA-S/prolactin ratios) had the most alterations as delayed effects of sulfur mustard. Also, DHEA-S/cortisol, DHEA-S/prolactin, testosterone/cortisol, and prolactin/cortisol had the most contributing in changes of hormone profile for SM-induced pulmonary disorders. These data may suggest the best parameters for evaluating of hormone profile of SM-exposed people.

Transcription of biological aging markers (ANRIL, P16INK4a, TBX2, and TERRA) and their correlations with severity of sulfur mustard exposure in veterans

Sulfur mustard (SM) exposure has delayed harmful effects, including premature biological aging. This study aimed to evaluate the expression of aging markers (i.e., ANRIL, P16INK4a, TBX2, and TERRA) and assess their correlation with the severity of SM exposure in the long term. The study was conducted on two volunteer groups. 1) SM-exposed group, exposed to SM once in 1987 during the war; divided into three subgroups based on the injury severity, asymptomatic (without any clinical signs), mild, and severe; 2) Non-exposed group. In the SM-exposed group, ANRIL transcript was decreased, especially in subgroups of mild and severe. TBX2 transcript was also decreased in the total SM-exposed group. This decrease was more significant in the mild and severe subgroups than in asymptomatic ones. P16INK4a transcript was increased in the SM-exposed group, especially in the asymptomatic subgroup. The increase in TERRA transcript was also significant in all subgroups. There was a positive correlation between the TERRA transcript and the severity of injury, while this correlation was negative for the ANRIL. It is concluded that the delayed toxicity of SM may be associated with dysregulation of aging markers leading to premature cellular aging. These markers' alterations differed according to the severity of SM injury.

Canine sperm motility is associated with telomere shortening and changes in expression of shelterin genes

BACKGROUND

Motion quality is a critical property for essential functions. Several endogenous and exogenous factors are involved in sperm motility. Here, we measured the relative telomere length and evaluated the gene expression of its binding-proteins, shelterin complex (TRF1, TRF2, RAP1, POT1, TIN2, and TPP1) in sperm of dogs using relative quantitative real-time PCR. We compared them between two sperm subpopulations with poor and good motion qualities (separated by swim-up method). Telomere shortening and alterations of shelterin gene expression result from ROS, genotoxic insults, and genetic predisposition.

RESULTS

Sperm kinematic parameters were measured in two subpopulations and then telomeric index of each parameter was calculated. Telomeric index for linearity, VSL, VCL, STR, BCF, and ALH were significantly higher in sperms with good motion quality than in sperms with poor quality. We demonstrated that poor motion quality is associated with shorter telomere, higher expression of TRF2, POT1, and TIN2 genes, and lower expression of the RAP1 gene in dog sperm. The levels of TRF1 and TPP1 gene expression remained consistent despite variations in sperm quality and telomere length.

CONCLUSION

Data provided evidence that there are considerable changes in gene expression of many shelterin components (TRF2, TIN2, POT1and RAP1) associated with shortening telomere in the spermatozoa with poor motion quality. Possibly, the poor motion quality is the result of defects in the shelterin complex and telomere length. Our data suggests a new approach in the semen assessment and etiologic investigations of subfertility or infertility in male animals.

Increased serum lipofuscin associated with leukocyte telomere shortening in veterans: a possible role for sulfur mustard exposure in delayed-onset accelerated cellular senescence

BACKGROUND

Sulfur mustard (SM) is a toxic gas that causes chronic inflammation and oxidative stress leading to cell senescence. This study aimed to evaluate two indicators of biological aging (i.e., serum lipofuscin level and leukocyte telomere length) and assess their relationship based on the severity of SM exposure in the long term.

METHODS

The study was performed on two groups of male participants. 1) SM-exposed group (exposed to SM once in 1987), 73 volunteers. 2) Non-exposed group, 16 healthy volunteers. The SM-exposed group was categorized into three subgroups based on the severity of SM exposure and body damage (asymptom, mild, and severe). The blood sample was prepared from members of each group. The serum lipofuscin, TGF-β, malondialdehyde (MDA), c-reactive protein (CRP), and leukocyte telomere length (TL) were measured in all participants.

RESULTS

The MDA level was increased in the SM-exposed group (mean = 39.6 µM, SD = 16.5) compared to the non-exposed group (mean = 21.1 µM, SD = 10.3) (P < 0.05). The CRP level was also increased in the SM-exposed group (mean = 5.12 mg/l, SD = 3.36) compared to the non-exposed group (mean = 3.51 mg/l, SD = 1.21), while the TGF-β level was decreased (P < 0.05) in the SM-exposed group (mean = 52.6 pg/ml, SD = 18.7) compared to the non-exposed group (mean = 68.9 pg/ml, SD = 13.8). The relative TL was shorter in the SM-exposed group (mean = 0.40, SD = 0.28) than in the non-exposed group (mean = 2.25, SD = 1.41) (P < 0.05). The lipofuscin level was higher in the total SM-exposed group (mean = 1.44 ng/ml, SD = 0.685) than in the non-exposed group (mean = 0.88 ng/ml, SD = 0.449) (P < 0.05). The MDA and CRP levels were increased in the SM-exposed subgroups of asymptom, mild, and severe than the non-exposed group, while TGF-β level and TL were decreased in those subgroups. The lipofuscin level was higher in the SM-exposed subgroups of mild and severe than in the non-exposed group. The regression analysis determined a negative correlation between lipofuscin level and TL. The lipofuscin/TL ratio was higher in the total SM-exposed group (mean = 6.36, SD = 5.342) than in the non-exposed group (mean = 0.51, SD=0.389). This ratio was also higher in the SM-exposed subgroups of asymptom, mild, and severe than in the non-exposed group. The lipofuscin/TL ratio did not differ between mild and severe subgroups.

CONCLUSION

The delayed toxicity of SM is associated with chronic oxidative stress, continuous inflammatory stimulation, increased lipofuscin, and telomere shortening. Future studies are needed to verify the suitability of serum lipofuscin to telomere length ratio in determining the severity of SM toxicity.